Article II Section II Clause II of the constitution already gives Congress the power to make treaties, advise and consent.
No need to introduce a bill for that, they just have to have enough courage to tell Obama no.
You are right but Congress waived the power they had by allowing 94 Presidential agreements to stand as treaties unchallenged. Senator Paul and Corker wisely seek to reassert the power of Congress that the Congress has squandered on political laziness and expedience.